The present invention relates to a method and table assembly for applying coatings to spherical components.
Surface coating processes are widely used to produce high-quality thin films and coatings on components to increase wear resistance and provide other desirable properties. A variety of coating techniques are available for this purpose. For example, sputtering is a specific physical vapor deposition (PVD) coating process in which an inert gas, such as argon, is ionized in a vacuum chamber containing the component to be coated and a sputtering target. The argon ions bombard the sputtering target, dislodging target material atoms that then strike and coat the component. To increase the sputter rate and thereby decrease the time required to form the coating, a magnet can be used to produce a magnetic field closed-loop path to keep the free electrons near the target material, i.e., magnetron sputtering. In unbalanced magnetron sputtering, extra magnetic coils intensify the plasma close to the product, resulting in a denser coating. As a further refinement, known as closed field unbalanced magnetron sputtering, the magnets can be configured in such a way that the magnetic field confines the plasma and less target material is lost to the chamber walls.